Mobile phone-based electrochemiluminescence sensing exploiting the ‘USB On-The-Go’ protocol

• Published in: Sensors and actuators. B, Chemical Chemical, 2015-09, Vol.216, p.608-613
• Main Authors: Doeven, Egan H., Barbante, Gregory J., Harsant, Anthony J., Donnelly, Paul S., Connell, Timothy U., Hogan, Conor F., Francis, Paul S.
• Format: Article
• Language: English
• Subjects: Calibration; Cameras; Control systems; Data buses; Electrochemiluminescence; Electrogenerated chemiluminescence; Emittance; Mobile phone sensor; Operating systems; Portable analytical devices; Smartphone sensor; Smartphones
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2015.04.087

A low-cost system to generate, control and detect electrochemiluminescence using a mobile smartphone is described. A simple tone-detection integrated circuit is used to switch power sourced from the phone's Universal Serial Bus (USB) ‘On-The-Go’ (OTG) port, using audible tone pulses played over the device's audio jack. We have successfully applied this approach to smartphones from different manufacturers and with different operating system versions. ECL calibrations of a common luminophore, tris(2,2′-bipyridine)ruthenium(II) ([Ru(bpy)3]2+), with 2-(dibutylamino)ethanol (DBAE) as a co-reactant, showed no significant difference in light intensities when an electrochemical cell was controlled by a mobile phone in this manner, compared to the same calibration generated using a conventional potentiostat. Combining this novel approach to control the applied potential with the measurement of the emitted light through the smart phone camera (using an in-house built Android app), we explored the ECL properties of a water-soluble iridium(III) complex that emits in the blue region of the spectrum. The iridium(III) complex exhibited superior co-reactant ECL intensities and limits of detection to that of the conventional [Ru(bpy)3]2+ luminophore.